VB.NET String

In VB.NET, string is a sequential collection of characters that is called a text. The String keyword is used to create a string variable that stores the text value. The name of the string class is System.String that contains the various function of string.

Declaration and Initialization of String

The following are the different ways to declare and initialize the string variable using the String keyword in the VB.NET programming language.

  ‘Declaration of the String variable  Dim str As String  Dim abc As String    ‘ Initialization of String variable  Dim str As String = “Welcome to Tutor Aspire.”  Dim str1 As String = “Hello World!”    ‘ Initialize a null string  Dim str2 As String = Nothing    ‘ Initialization of an empty string  Dim name As String = String.Empty     ‘ Creating a String from char  Dim letter As Char() = {“H”, “E”,  “L”, “L”, “O” }  

In the above declaration of string, we have defined the string variable with string keyword and initialize string variable with value based on our requirements.

Creating a String Object

There are different ways to create a string object in the String.

To use a String class constructor.
By using the property or calling method to return a string.
Use a string literal to define a string variable.
Use a String concatenation operator (+).
By using a formatting function to convert a value or object into the string representation of the object.

Let’s create an example to demonstrates the uses of String objects.

String_object.vb

  Imports System  Module String_object      Sub Main()          Dim str, str2, fullname, data As String          str = “Hello”          str2 = “World!”          fullname = str + ” ” + str2          Console.WriteLine(” Message is {0}”, str)          Console.WriteLine(” Message is {0}”, str2)          Console.WriteLine(” Fullname is {0}”, fullname)            ‘ By using string constructor          Dim str3 As Char() = {“H”, “e”, “l”, “l”, “o”}          data = New String(str3)              Console.WriteLine(” Your message is {0}”, data)            ‘ Use of returning string          Dim arr() As String = {” Hello”, “Welcome”, “to”, “tutoraspire”}          Dim msg As String = String.Join(” “, arr)          Console.WriteLine(” You have defined these parameters as string array {0}”, msg)            ‘Use of Formatting method to convert a value to the string          Dim time As DateTime = New Date(2020, 6, 18, 18, 48, 2)          Dim sentmsg As String = String.Format(” Your message has been successfully sent at {0:t} on {0:D}”, time)          Console.WriteLine(” Your text is that {0}”, sentmsg)          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

Immutable string object

In VB.NET, the string object is immutable. It means that once we have created a string object, it cannot be modified during its execution. And if we modified an existing value in a string object through addition and subtraction, it discards the old value of instance in memory and creates a new instance to hold a new value. Furthermore, if we want to perform any operation in the String object, we must define an object every time to create a new String object. So, in that case, the string provides the System.Text.StringBuilder class to modify a string without creating a new object.

Properties of the String Class

Following are the two properties of string class:

Chars: It is used to get the character from the current string object.
Length: It is used to return the number of characters in the current string object.

Access individual characters from Strings in VB.NET

In VB.NET, we can access the individual character from the current string object with index values.

Let’s write a program to access the individual characters from the string by defining an index position.

Get_Chars.vb

  Imports System  Module Get_Chars      Sub Main()          Dim i As Integer          ‘ Declaration of String variable          Dim name As String = “Hello World!”          Console.WriteLine(” These are Characters in Hello World! String :”)          For i = 0 To name.Length – 1 ‘ Count from 0 to Length – 1              Console.WriteLine(name(i))          Next          Console.WriteLine(“Length is {0}”, name.Length) ‘ Use of Length Properties          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module   

Output:

VB.NET String

In the above program, a For loop is continuously executed each element of the String variable’s value is Hello World! Until the condition (name.Length -1) is reached. Here, Length function is used to count the number of characters in the string.

There are various functions of string class that helps to manipulate the string objects.

1. Compare(): It is used to compare two specified string objects, and if the string is less than another string object, it returns an integer value.

Syntax:

The returned integer value represents the relationship between two specified string objects. The following table shows the string comparison condition that returns the integer value after comparing two specified string items.

Compare String Condition	It returns an integer value
Str1 == Str2	0
Str1 > Str2	1
Str1 < Str2	-1

Example: Write a program to understand the uses of Compare() function in String Class.

String_cmp.vb

  Imports System.String  Module String_cmp      Sub Main()          ‘Definition of local String variable          Dim Str1 As String = “Hello”          Dim Str2 As String = “Cello”          ‘ Use of String.compare() function          Console.WriteLine(” Comparison of String {0} and {1} result is {2}”, Str1, Str2, String.Compare(Str1, Str2))            Dim Sdata As String = ” WELCOME”          Dim Sdata2 As String = ” Welcome”          ‘ Use of String.Compare() function          Console.WriteLine(” Comparison result of String {0} and {1} result is {2}”, Sdata, Sdata2, String.Compare(Sdata, Sdata2))            Dim Sdata3 As String = “Hello”          Dim Sdata4 As String = “Hello”          ‘ Use of String.Compare() function          Console.WriteLine(” Comparison result of String {0} and {1} result is {2}”, Sdata3, Sdata4, String.Compare(Sdata3, Sdata4))            Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above example, the string compare () method checks the values of two string variables and returns integer values.

2. Concat()

The Concat() function is used in string class to join two or more strings or append one string to the end of another string. It is useful when we need to combine two or more text to make a sentence, and it returns a new string.

Syntax:

And when we use more than three string parameters to combine, we have to define this way:

Syntax:

  Public Shared Function Concat( Str1 As String, Str2 As String, Str3 As String ) As String  

Let’s create a program to understand the uses of the Concat() function to append or concatenate one or more strings in the VB.NET programming language.

String_concate.vb

  Imports System.String  Module String_concate      Sub Main()          ‘ Definition of local variables          Dim str As String = “Learn”          Dim Str2 As String = ” ” & “VB.NET Programming Language”          ‘Use of Concat() function to combine two string variable          Console.WriteLine(“Your String is {0}”, String.Concat(str, Str2))            Dim val As String = “Want to”          Dim val2 As String = ” ” & “Learn String methods”          Dim str3 As String = ” ” & “in VB.NET language?”          ‘Use of Concat() function to combine two or more string variable            Console.WriteLine(“Your Sentence is {0}”, String.Concat(String.Concat(val, val2), str3))          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above program, we used a Concat() function to combine one or more strings to return a single string.

3. Contains(): It is used to validate whether the specified text or parameter exists in the current string. If the text is existing in the string, it returns a true Boolean value; otherwise, it returns false.

Syntax:

Let’s create a program to understand the uses of the Contains() function to check whether the particular string exists or not in a given string.

String_contain.vb

  Imports System.String  Module String_contain      Sub Main()          ‘Definition of local variables          Dim msg As String = “Welcome to VB.NET Language.”          Dim txt As String = “VB.NET”            ‘ Use of Contains() function          Console.WriteLine(“Does {0} String Contains {1}? :{2}”, msg, txt, msg.Contains(txt))            Dim str As String = “String is the collection of characters.”          Dim strtxt As String = “Collection”            ‘Use of Contains function          Console.WriteLine(“Does {0} Sentence Contains {1}? :{2}”, str, strtxt, str.Contains(strtxt))            Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above program, the String Contains() function is to determine whether the given string str contains the value of strtext, and if the value exists in the str, it returns a true value; otherwise, it returns false.

4. String Copy(): In the String class, there is a Copy() function used to create a new string object with the same content or value specified in the original string.

Syntax:

Let’s create a program to understand the uses of Copy() function in the VB.NET programming language.

String_copy.vb

  Imports System.String  Module String_Copy      Sub Main()          ‘Declaration and Initialization of local variable          Dim str As String = ” Welcome to Tutor Aspire”          ‘ Use String.Copy() function          Dim str2 As String = String.Copy(str)          Console.WriteLine(” Text in First String is {0}”, str)          Console.WriteLine(” Copy text is {0}”, str2)            ‘ Use String.Copy() function          Console.WriteLine(“Text in Copy String : {0}”, String.Copy(str))          Console.WriteLine(” Does the Object reference equal? {0}”, Object.ReferenceEquals(str, str2))            Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

5. CopyTo(): A CopyTo () function is used to copy the specified number of characters from the original string object.

Syntax:

  Public Sub CopyTo( sourceIndex As Integer, destination As Char(), destinationIndex As Integer, count As Integer )  

Create a simple program of the CopyTo() function to copy a string in the VB.NET programming language.

String_CopyTo.vb

  Imports System.String  Module String_CopyTo      Sub Main()        ‘ Declaration of String variable          Dim data As String = “Welcometotutoraspire”  ‘ Declaration of strcpy array          Dim strcpy(25) As Char          Console.WriteLine(“Original String is: {0}”, data)  ‘ use CopyTo() method          data.CopyTo(9, strcpy, 0, 10)          Console.WriteLine(“Copied character is ” + strcpy)          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

6. EndsWith(): The EndsWith() function is used to check whether the text or parameter specified in the original string ended with the specified text.

Syntax:

Let’s create a program to understand the uses of EndsWith() function in the VB.NET programming language.

String_With.vb

  Imports System.String  Module String_With      Sub Main()          ‘Definition of String variable          Dim str As String          str = ” VB.NET is the best programming language”          ‘ Use of EndsWith() function in String Class          If str.EndsWith(“language”) = True Then              Console.WriteLine(” The String statement EndsWith ‘language'”)          Else              Console.WriteLine(” The string is not EndsWith ‘Language'”)          End If          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above program, the EndsWith() function is checked whether the defined text ‘language’ specified in the original string object str ends with the word language.

7. Equals(): As the name defines, an Equals() function is used in the string class to determine if both string objects have the same value or not. If the value is the same, the Equals() string methods are true; otherwise, it returns false. And if both objects have null values, the Equals() function returns a true value.

Syntax:

Let’s create a program to understand the uses of EndsWith() function in the VB.NET programming language.

Equal_String.vb

  Imports System.String  Module Equal_String      Sub Main()          ‘Definition of local variable          Dim str = “Welcome”          Dim str2 = “welcome”          ‘Use of Equals() function          Console.WriteLine(“Are string {0} and {1} equal? : {2}”, str, str2, String.Equals(str, str2))          Dim str3 = “Welcome”          Console.WriteLine(“Are string {0} and {1} equal? : {2}”, str, str3, String.Equals(str, str3))          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above example, the String Equals() method checks whether the specified strings object is equal. If yes, it returns True value; otherwise, it returns False.

8. String Format(): The Format() function is used to replace one or more objects with the specified string object. By using the Format() function, we can insert the value of a variable into another object string.

Syntax:

Let’s create a program to understand the uses of Format() function in the VB.NET programming language.

String_Format.vb

  Imports System.String  Module String_Format      Sub Main()          ‘ Declaration and Represntation of Format String          Dim rep_string As String = ” Tutorial: {0}, Topic: {1}, Method Name: {2} ”            ‘Use of String.Format() function          Dim spec_string As String = String.Format(rep_string, “VB.NET”, “String”, “Format_String”)            Console.WriteLine(” Representation of String is {0}”, spec_string)          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above example, the string Format() method has replaced the format objects {0} with “VB.NET”, {1} with “String” and {2} with “Format_String”.

9. IndexOf(): The String IndexOf() function is used to return the index position of the first occurrence of the specified character or string in the original string object, followed by the zero (0) index. Furthermore, we can also define the starting index position of the specified character or string in the original string.

Syntax:

  ‘Getting a Char:  Public Function IndexOf( ByVal As Char ) As Integer    ‘For Getting a String:  Public Function IndexOf( ByVal As String ) As Integer    ‘Define the starting position of the character  Public Function IndexOf( ByVal As Char, StartIndex As Integer ) As Integer    ‘Define the starting position of the String  Public Function IndexOf( ByVal As String, StartIndex As Integer ) As Integer  

Let’s create a program to understand the uses of IndexOf() function in VB.NET programming language.

indexOf_String.vb

  Imports System.String  Module indexOf_String      Sub Main()          Dim Str As String = “tutoraspire”          Dim txt As String = “Welcome to Tutor Aspire Site”          ‘ Use of IndexOf() function to get specified character position          Console.WriteLine(” Occurrence of character T index position {0}”, Str.IndexOf(“T”))            ‘ Use of IndexOf() function to get the Specified String position of specified String          Console.WriteLine(” Occurrence of String position {0}”, txt.IndexOf(“tutoraspire”))            ‘Starting position of p is 5          Console.WriteLine(” Define the starting position of the Character p is {0}”, Str.IndexOf(“p”, 5))            ‘Starting position of tutoraspire is 5          Console.WriteLine(” Define the starting position of the String ‘tutoraspire’ is {0}”, txt.IndexOf(“tutoraspire”, 11, 15))            Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above example, we used an IndexOf() function to get the specified position of a character or string from the original string in VB.NET programming.

10. Insert(): The Insert() function of the String class is used to insert a specified string at the specified position in the original string object.

Syntax:

Let’s create a program to understand the uses of Insert() function in the VB.NET programming language.

String_Insert.vb

  Imports System.String  Module String_Insert      Sub Main()          Dim name = ” Welcome to Site”          Dim str_name = “tutoraspire”          ‘Use of Insert() function          Console.WriteLine(” Inserted String {0} into Original string is {1}”, str_name, name.Insert(11, ” tutoraspire”))          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

11. Remove(): The remove function is used to remove or delete characters at the specified position until the end of the defined string object. Furthermore, we can use the remove () function to remove a set of characters by defining the beginning and end positions of the characters to be removed from the original string.

Syntax:

  Remove Single Character  Public Function Remove( StartIndex As Integer ) As String  Set of Character  Public Function Remove( StartIndex As Integer, Length As Integer) As String   

Let’s create a program to understand the uses of Insert() function in the VB.NET programming language.

String_Remove.vb

  Module String_Remove      Sub Main()          Dim str As String = ” Welcome to Tutor Aspire Site”          ‘ For Single Character          Console.WriteLine(” Remove a Single character {0}”, str.Remove(3))            ‘ For Group of character          Console.WriteLine(” Remove a set of character from the original String {0}”, str.Remove(1, 3))          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

12. Replace(): The String Replace() function is used to replace all the occurrence of a specified character or string from the original string object and then return a new string.

Syntax:

  // Get the replace char  Public Function Replace ( oldValue As Char, newChar As Char ) As String  // Get the replace String  Public Function Replace (oldValue As String, newValue As String) As String  

Let’s create a program to understand the use of Replace() function in the VB.NET programming language.

String_Replace.vb

  Imports System.String  Module String_Replace      Sub Main()            Dim ch As String = “abababab”          ‘Use Replace() function to replace Single Character          Dim strchar As String = ch.Replace(“a”, “c”)          Console.WriteLine(” Old Value is {0}”, ch)          Console.WriteLine(” New Value is {0}”, strchar)            Dim str As String = “It’s Okay not to be Okay”          ‘Use Replace() function to replace String          Dim nstr As String = str.Replace(“Okay”, “Fine”)          Console.WriteLine(” Old String is {0}”, str)          Console.WriteLine(” New String is {0}”, nstr)            Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above example, we used a Replace() function to replace a specified character or string from the given string in the VB.NET programming.

13. Join(): As the name suggests, a Join() function is used to concatenate all the specified elements of the string array using the specified separator.

Syntax

  Public Shared Function Join ( Separator As String, paramArray Value As String() ) As String  

Let’s create a program to understand the uses of Join() function in the VB.NET programming language.

String_Join

  Imports System.String  Module String_Join      Sub Main()          Dim strArray() As String = {“Hello”, “Welcome”, “to”, “tutoraspire”, “Site”}          ‘Use of String.Join() function          Dim strSep As String = String.Join(“-“, strArray)          Console.WriteLine(” Join String using the Hypen: {0}”, strSep)            Dim textArray() As String = {“want to learn”, “VB.NET programming Language”, “?”, “Join”, “the tutoraspire Site”}          ‘Use the String.Join() function with Space (vbCrLf) Seperator              Console.WriteLine(” Text is {0}”, String.Join(vbCrLf, textArray))          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()        End Sub  End Module  

Output:

VB.NET String

In the above program of String Join() function, we used hyphen (-) and comma (,) separator to concatenates all the elements of the string array.

14. Split(): As the name suggests, the string Split() function is used to split a given string into substrings with the help of delimiters that are used to split a string in VB.NeT programming language. Furthermore, we can specify the number of characters that should be returned in the substring.

Syntax:

  Public Function Split (ParamArray separator As Char() ) As String()  ‘ Specifies the character length  Public Function Split (ByVal separator As Char(), count As Integer) As String  

Let’s create a program to understand the uses of the Split() function in the VB.NET programming language.

String_Split.vb

  Imports System.String  Module String_Split      Sub Main()          Dim str As String = “Welcome-to-tutoraspire”          ‘Use of Split() function          Dim txtArray As String() = str.Split(New Char() {“-“c})          For i As Integer = 0 To txtArray.Length – 1                Console.WriteLine(txtArray(i))          Next          Console.WriteLine(” Press any key to exit…”)              Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above example, we used a Split() function to split the given string (Welcome-to-tutoraspire”) with a separator hyphen (-), and it returns a split string as an array. And the For loop is used to display each item of an array element.

15. StartsWith(): The StartsWith() function of String class is used to determine whether the string’s beginning is matched with a specified string object. If the string is matched, it returns True value; otherwise, it shows False.

Syntax:

Let’s create a program to understand the uses of StartsWith() function in the VB.NET programming language.

String_StartsWith.vb

  Imports System.String  Module String_StartsWith      Sub Main()          Dim str As String = “Welcome to Tutor Aspire”          Dim stwith As String = “Welcome”          Dim st As String = “to”          ‘ Use of StartsWith() function          Console.WriteLine(” String is {0}”, str)          Console.WriteLine(” Does the string start with ‘{0}’? : {1}”, stwith, str.StartsWith(stwith))          Console.WriteLine(” Does string start with ‘{0}’? : {1}”, st, str.StartsWith(st))          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  Output:   String is Welcome to Tutor Aspire   Does the string start with ‘Welcome’? : True   Does string start with ‘to’? : False   Press any key to exit…  

In the above program, we used StartsWith() function to validate whether the given string starts with “Welcome”. If yes, returns True; otherwise, it shows False.

16. ToLower: The ToLower function of String class is used to convert any string object into Lower Case.

17. ToUpper: The ToUpper function of String class is used to convert a string object into Upper Case.

Let’s create a program to understand the uses of ToLower and ToUpper function in the VB.NET programming language.

String_cases.vb

  Imports System.String  Module String_cases      Sub Main()          Dim str As String = “tutoraspire”          Dim txt As String = ” VB.NET TUTORIAL”          ‘Use ToUpper and ToLower method in String Class          Console.WriteLine(“String converted into Upper Case is {0}”, str.ToUpper)          Console.WriteLine(“String converted into Lower Case is {0}”, txt.ToLower)          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

In the above program, we used ToLower and ToUpper method in String class to convert a given string into the Upper and Lower case of the VB.NET programming.

18. Trim(): The Trim() Function is used to remove all occurrence of leading and trailing whitespace, characters and special symbols from the specified string object.

Syntax:

  Public Function Trim() As String  Public Function Trim( trimChars As Char()) As String  

The First Syntax of Trim() function represents that it is used to remove all whitespaces from the starting and end of the given string.

The Second Syntax represents that it is used to trim all specified characters from the starting and end of the given string object.

Let’s create a program to understand the uses of the Trim() function in the VB.NET programming language.

Trim.vb

  Imports System.String  Module Trim      Sub Main()          Dim txt As String = ”   VB.NET is the       ”          Dim ttxt As String = ”   Best Tutorial   ”          Console.WriteLine(” Before Trim the String {0} {1}”, txt, ttxt)          ‘Use of Trim() Function to remove WhiteSpace          Console.WriteLine(” After Trimming {0} {1}”, txt.Trim(), ttxt.Trim())            ‘Definition of Char() Array          Dim trimChar As Char() = {“$c”, “@”, “&”, “#”}          Dim str As String = “$$## VB.NET is the Best Tutorial &&&@@@”          Console.WriteLine(” Before Trim : {0}”, str)          ‘ USe of Trim() function to remove character          Console.WriteLine(” After Trim : {0}”, str.Trim(trimChar))          Console.WriteLine(” Press any key to exit…”)          Console.ReadKey()      End Sub  End Module  

Output:

VB.NET String

Next TopicVB.NET ArrayList

VB.NET String

VB.NET String

Declaration and Initialization of String

Creating a String Object

Immutable string object

Properties of the String Class

Access individual characters from Strings in VB.NET

Introduction to Unity

Verbal Ability | Change of Speech

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